CHEAPEST USB ASYNC AUDIO1 USING ST32F401RB

knows bugs:

• none.
• 1,noise bug fixed in v20231112,noise bug is not cause by data lost, its cause by i2s itself.
• time between i2s stop and restart must have delay.

2024.3.17

• fix V4w UVproject (microlib not check,some gpio wrong).

2024.3.5

• audio buffer size veriable.
• 6K buffer for 88K 96K , reduce underrun.
• main: use systick timer.

2023.11.12

• add: probably missing dma reset before play
• sequence changed: time between i2s stop and restart must have delay.

2023.10.3

• add UART log ring buffer ,get out of 'while' when print
• hw ad1955 is ok
• work for H81 motherboard usb compbility
• change panel LED display

2022.5.28

• HW seprate folder,(only ak4396 is work done now,other working in process).
• remove LICENSE,it's only for fun.

2022.5.27

• improve usb setup--audio class,fix mute/vol,

2020 to 2021

• add many HW board configs

2019.12

• add 24bit, add 48/88/96k audio streaming formats.
• fix audio buffer overflow 2words

initial release

• support 32bit.44k format
• async using osc input to stm32f4 i2s_ckin pin,cpld device not required anymore. (please see the schemaitcs for more infomation).
• test with "xmos stereo driver",win10,linux.